A calcium reactor is one of the better things you can do for your system. Not only can you adjust your calcium level anywhere you wish, even greater than 500 PPM, a calcium reactor also allows for very stable PH, in the 8.2 - 8.4 range, and alkalinity greater than 2.5. And its all automatic following initial set-up. Your clams and LPS corals will open wider and be healthier. I dosed Kalkwasser for some time with less than optimal results. A calcium reactor is the only way to go. Some are expensive. Check out MyReefCreations.com. He will build a anything from a small system, to a system sized for an aquarium at Sea World, reasonably. Be patient, it takes a little longer than you might anticipate. But the quality is good, and the price is excellent. Get one. You'll love it.